docstr: Get the next batch from the block buffer.
  
  Returns:
      A batch represented as a Block.
docstr_tok: ["Get","the","next","batch","from","the","block","buffer",".","Returns",":","A","batch","represented","as","a","Block","."]
code: def next_batch(self) -> Block:
      """Get the next batch from the block buffer.
  
      Returns:
          A batch represented as a Block.
      """
      raise NotImplementedError()
  
imports: from typing import Optional
  from ray.data._internal.arrow_block import ArrowBlockAccessor
  from ray.data._internal.arrow_ops import transform_pyarrow
  from ray.data._internal.delegating_block_builder import DelegatingBlockBuilder
  from ray.data.block import Block, BlockAccessor
label_desc: Use image node_id 5 for calling the BatcherInterface obj's underlying member method code with example usage: obj.next_batch() without return types